<template>
  <view>
    <!-- 使用自定义的搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滑动区域 -->
      <scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
        <block v-for="(item,i) in cateList" :key="i">
          <view :class="['left-scroll-view-item',i===active?'active':'']" @click="activeChange(i,item)">
            {{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧的滑动区域 -->
      <scroll-view scroll-y="true" :scroll-top="scrollTop"  style="background-color: #fff;" :style="{height: wh + 'px'}">
        <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
          <!-- 二级分类的标题 -->
          <view class="cate-lv2-title">/{{item2.cat_name}}/</view>
          <!-- 当前二级分类下的三级分类列表 -->
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
              <!-- 三级分类的图片 -->
              <img :src="item3.cat_icon" alt="">
              <!-- 三级分类的文本 -->
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  // 导入自己封装的mixin模块
  import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
    data() {
      return {
        wh: 0, // 当前设备可用的高度
        cateList: [], // 分类数据
        active: 0,
        cateLevel2: [], // 二级分类的数据
        scrollTop: 0, // 滚动条距离顶部的距离
      };
    },
    // 将badgeMix混入到当前到当前的页面中进行使用
    mixins: [badgeMix],
    onLoad(){
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      // 调用获取分类列表数据的方法
      this.getCateList()
    },
    methods:{
      async getCateList(){
        const {data:res} = await uni.$http.get('/api/public/v1/categories')
        if(res.meta.status !== 200) return uni.$showMsg
        this.cateList = res.message
        
        // 获取二级分类的数据
        this.cateLevel2 = res.message[0].children
      },
      activeChange(i,item){
        this.active = i
        // 为二级分类赋值
        this.cateLevel2 = item.children
        // 让scrollTop的值在0与1之间切换
        this.scrollTop = this.scrollTop ? 0:1
      },
      // 跳转到商品列表页面
      gotoGoodsList(item3){
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid='+item3.cat_id
        })
      },
      gotoSearch(){
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss">
.scroll-view-container{
  display: flex;
  
  .left-scroll-view{
    width: 120px
  }
  
  .left-scroll-view-item{
    background-color: #f7f7f7;
    line-height: 60px;
    text-align: center;
    font-size: 12px;
    
    &.active{
      background-color: #fff;
      position: relative;
      
      &::before{
        content: '';
        display: block;
        width: 3px;
        height: 30px;
        background-color: #c00000;
        position: absolute;
        top: 50%;
        left: 0;
        // margin-top: -15px;
        transform: translateY(-50%)
      }
    }
  }
}

.cate-lv2-title{
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}

.cate-lv3-list{
  display: flex;
  flex-wrap: wrap;
  
  .cate-lv3-item{
    width: 33%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin-bottom: 10px;
    
    img{
      width: 60px;
      height: 60px;
    }
    text{
      font-size: 12px
    }
  }
}
</style>
